1. Field of the Invention
The present invention relates to a process and apparatus for improving the quality of water by applying electrical energy thereto without using activated carbon, a filter, chemicals or the like. The process and apparatus are suitable for improving the taste of drinking water such as well water and city water.
Nowadays, a source of a water supply has been contaminated by an increase of waste water from houses due to popularization of flush toilets and bathes, discharge of various chemicals including detergents, increase of water in industrial use, discharge of various waste water, use of various chemical fertilizers and agricultural chemicals, so that the quality of well water and city water remarkably decreases. Therefor, there is a strong demand for the supply of drinking water to be safe and taste good.
2. Description of Related Art
As quality of modified water, hitherto, alkali-ionized water has been known. This water can be obtained by feeding water into an electrolytic cell partitioned by a diaphragm into an anode and cathode chambers to apply DC voltage between an anode and cathode in the chambers for causing a certain kind of electrolysis. An electrolyte such as NaCl or the like may be added to the water to increase an electric conductivity.
An alkaline water formed in the cathode chamber has been utilized as drinking water [Japanese Patent 61-101296(A) and 4-277076(A)], and an acidic water formed in the anode chamber has been utilized for sterilization purposes [Japanese Patent 1-317592(A)].
In such a conventional water treating process and apparatus, one of the electrodes is used as one with positive polarity, whereas the other with negative polarity, and therefore, the electrodes are gradually covered with matters deposited thereon through the treatment, thereby preventing transfer of electricity therebetween. For preventing the deposition, there is a way to periodically change the polarity of DC voltage to be applied to the electrodes.
With the mere periodic change of polarity in DC voltage, however, various and different requirements depending on usage of water can not be satisfied and sufficient effect can not be obtained by a single apparatus. Further, the periodic change of polarity requires an extra constant-voltage circuit, low current circuit, polarity reverse circuit and others which increase the cost therefor. PG,5
The conventional process utilizes the certain electrolysis which is unsuitable for treating a large amount of water, and in which solubility of minerals decreases, as pH of the water becomes 9-10. There are such disadvantages that the alkali-ionized drinking water has a bad effect on persons with hypersensitiveness such as atopic diseases, pollinosis and others.
In view of above state of the art, the invention has energetically studied and investigated to find that various items on pollution, for instance, turbidity, smell, amount of dissolved oxygen, chemical oxygen demand (COD), concentration of phosphate and others can be improved, that cohesion and precipitation of organic matters suspended and/or dissolved in water occur, and that solubility of minerals increases, by decreasing oxidation-reduction potential (ORP) of the water through an electrical treatment which causes no substantial change in pH, to establish the invention.